Six pre and 6 post distilled water samples (4 from RGR and 2 from Bldg. 15) were analyzed for microbial and chemical contaminants. The total trihalomethanes (THMs) level of 117 Mug/1 (average of 4 samples) in tap water from RGR exceeded EPA's maximum permissible level of 100 Mug/1 for potable drinking water. The levels of all other microbial and chemical contaminants were within EPA's maximum permissible levels of potable drinking water. Distillation reduced the total THMs including chloroform, a potential carcinogen, from 117 Mug/1 to an average level of less than 4 Mug/liter. In addition, the total organic halides and the elements: chlorine, bromine, sodium, barium, iodine, manganese, magnesium, copper, cerium, calcium, zinc and aluminum were reduced. These results indicate that distillation would provide a more standardized supply of water throughout the year. Levels were higher in the summer (122 Mug/1) and fall 211 Mug/1) than in the two spring samples (64 and 72 Mug/1). Rodent diets were examined for nutritional content, microbial (Salmonella sp.) and chemical contaminants. Results from each batch of diet were received prior to consumption. All batches that were shipped were accepted; however, one batch was withdrawn by the supplier because of low levels of Vitamin A. Test results were within the acceptable range for the chemical contaminants: arsenic, cadmium, lead, mercury, selenium, chlorinated hydrocarbons, PCB's, BHC's, organophosphates, aflatoxin, and nitrosamines. Each batch was negative for estrogenic activity by the mouse bioassay test and was culture negative for Salmonella sp.